1. Field of the Invention
The present invention relates to a golf club head for a wood type club and, more specifically, to a golf club head capable of increasing the distance of flight of the ball and enabling the player to hit the ball so that the ball will fly in the desired direction.
2. Description of the Related Arts
Generally, golf clubs, particularly, wood type golf clubs for obtaining a long flight distance of a golf ball, should be able to make the ball fly as far as possible. Since the correct control of the direction of flight of the ball results in an increase in the distance of flight of the ball, a golf club capable of enabling the player to hit the ball so that the ball will fly in the desired direction is desirable. In order to enhance the performance of the golf club, it is important to locate the sweet spot of the head, namely, the point of intersection at the face of a perpendicular line drawn between the center of gravity and the face, is located as near to the center of the face as possible by locating the center of gravity as low as possible, to concentrate the weight of the head as much as possible around the line connecting the center of gravity and the sweet spot of the head, and to increase the moment of inertia about the center of gravity of the head by locating the center of gravity of the head as near as possible to the backside of the head, to increase the depth of the center of gravity, namely, the distance from the center of gravity to the face.
Note, various attempts have been made to enhance the distance of flight of the ball and to improve the capability of the club to enable the player to make the ball fly in the desired direction.
Japanese Unexamined Utility Model Publication No. 58-182,765 discloses a golf club head comprising a head body provided with recesses formed in the face and sole thereof, respectively, and a hole formed so as to interconnect the recesses, characterized by a face plate, a sole plate, and a connecting part interconnecting the face plate and the sole plate which are formed integrally by filling the recesses and the hole with a hard filling material. The constitution of this golf club head is intended to enhance the repulsion characteristic of the golf club head. However, since the face plate, the sole plate, and the connecting part formed in the hole are formed integrally of the same material, the depth of the center of gravity is inevitably small even if the filling material has a comparatively large specific gravity, and hence the ball directing performance of the golf club head is deteriorated. Furthermore, integrally forming the face plate, the sole plate and the connecting part with the same material unavoidably raises the position of the center of gravity, and accordingly the sweet spot is located above the center of the face, whereas the connecting part extends backward from a position on the face below the center of the face. Therefore, the longitudinal axis of the connecting part does not coincide with the line interconnecting the sweet spot and the center of gravity, and hence the connecting part is unable to provide a sufficient mass effect, namely, repulsion characteristic. Accordingly, this golf club head is not expected to greatly increase the distance of flight of the ball.
Japanese Examined Utility Model Publication No. 54-43,790 discloses a golf club head comprising a high-resistance connective member horizontally extending backward from the backside of the face plate, and a side sole joined to the rear end of the connective member with a connective bar. Since the side sole is in the rear part of the head, the depth of the center of gravity of this golf club head is large. However, since the connective member does not extend perpendicularly to the face and the front end of the connective member is not located at the center of the face, the longitudinal axis of the bar-shaped weight does not coincide with the line interconnecting the center of gravity and the sweet spot of the head, and hence the golf club head is unable to provide a sufficient mass effect, namely, repulsion characteristic. Accordingly, this golf club head is not expected to greatly increase the distance of flight of the ball.
Japanese Examined Utility Model Publication No. 49-12,116 discloses a golf club head comprising a bar-shaped weight extending backward perpendicular to and substantially from the center of the face, and a nut-shaped weight joined to the rear end of the bar-shaped weight. In this golf club head, the bar-shaped weight has a flange-shaped head fitting a counterbore formed in the face plate, and the head of the bar-shaped weight is exposed. Therefore, the depth of the center of gravity of this golf club head is small, and hence the ball directing performance of this golf club head is not satisfactory. That is, the direction of the face of a golf club head having a small depth of the center of gravity is liable to deviate from the correct direction when a part other than the sweet spot hits against the ball; consequently, the ball directing performance of this golf club head is not satisfactory.